The continuation study examines developmental precursors in the formation of children's use and expectations to use medicines and abusable substances. Three hundred urban children (10 boys, 20 girls) Grades 3-7 at schools representing high, medium and low socioeconomic levels are eligible for reinterview three years following initial interview. The children's primary caretakers will also be interviewed. A children's health belief model (CHBM) has been developed which predicts children's health related behavior and expectations of health related behavior. Indices used in the Model have been evaluated for internal reliability. The continuation study permits evaluation of 1) the value of family behavior and attitudes in the CHBM, 2) the stability of selected variables in the CHBM over time, 3) the relationship of peers to family influences over time, and 4) the relationship between children and their primary caretakers on selected CHBM variables. Six hypotheses drawn from results of the first interview and prior studies will be tested. Descriptive information will also be obtained on children's knowledge of medicines and abusable substances, primarily alcohol, cigarettes, and marijuana. The continuation study follows a pilot study of 64 urban children and a study of 420 urban children from which the proposed study population will be drawn. A register of the children will be established to permit future longitudinal studies. An interdisciplinary research team includes a pharmaceutical sociologist, medical anthropologist, developmental psychologist, and biostatistician. Information gained from the study will be useful for health professionals, persons studying children's health beliefs and behaviors, and persons planning and evaluating children's health education and abusable substances intervention programs.